1. Field of the Invention
The present invention relates to an injection-locked RF receiver having trifilar transformer splitter.
2. Description of the Related Art
The conventional RF receiver for digital modulation signal, for example a quadrature demodulation receiver, is classified as a coherent demodulation receiver. It divides the receiving signal into in-phase demodulation path and quadrature-phase demodulation path, and utilizes a local oscillation unit to synchronize with the receiving signal. Therefore, it has stable demodulation quality and high sensitivity for RF operation. However, the conventional scheme must utilize one local oscillation unit to lead high power consumption, thus it can not be used for low power consumption requirement of short-range wireless systems.
The conventional injection-locked technique can obtain frequency demodulation. By conversion of frequency and amplitude, the conventional injection-locked receiver can demodulate digital modulation formation of frequency modulation. However, the demodulation bandwidth of the conventional injection-locked receiver is limited by the injection-locked bandwidth. The injection-locked oscillation technique can non-coherent demodulate digital modulation formation for frequency modulation (FM), amplitude-shift keying (ASK) and frequency-shift keying (FSK) etc. However, the above schemes are limited by the injection-locked bandwidth of the injection-locked oscillator, thus it is difficult that they can obtain high sensitivity requirement for wireless communication system.
Therefore, it is necessary to provide an injection-locked RF receiver having trifilar transformer splitter to solve the above problems.